Lock manufacturer Kwikset recently introduced its SmartCode series, a keyless entry system to replace existing door hardware.

As an alternative to keyed-entry systems, the SmartCode series allows you to create two personalized access codes -- one for you, and one for a guest, contractor, or anyone else in need of temporary entry to your home. 

Locks can be rekeyed at any time for new guests.

A popular feature of the SmartCode series is its motorized, 1-inch deadbolt.  The deadbolt opens upon unlocking, eliminating the need to "turn a handle" to open -- just push the door.

The SmartCode operates on 4 AA batteries and can be purchased from Amazon.com for $86.27 plus free shipping.